#include <jtag/tapc.h>

/* tap_move[i][j]: tap movement command to go from state i to state j
 * encodings of i and j are what tap_move_ndx() reports.
 *
 * DRSHIFT->DRSHIFT and IRSHIFT->IRSHIFT have to be caught in interface specific code
 */
struct tms_sequences
{
	uint8_t bits;
	uint8_t bit_count;
};

/*
 * These macros allow us to specify TMS state transitions by bits rather than hex bytes.
 * Read the bits from LSBit first to MSBit last (right-to-left).
 */
#define HEX__(n) 0x##n##LU

#define B8__(x) \
	((((x)&0x0000000FLU) ? (1 << 0) : 0) + (((x)&0x000000F0LU) ? (1 << 1) : 0) + (((x)&0x00000F00LU) ? (1 << 2) : 0) + (((x)&0x0000F000LU) ? (1 << 3) : 0) + (((x)&0x000F0000LU) ? (1 << 4) : 0) + (((x)&0x00F00000LU) ? (1 << 5) : 0) + (((x)&0x0F000000LU) ? (1 << 6) : 0) + (((x)&0xF0000000LU) ? (1 << 7) : 0))

#define B8(bits, count)                       \
	{                                         \
		((uint8_t)B8__(HEX__(bits))), (count) \
	}

static const struct tms_sequences old_tms_seqs[6][6] = {
	/* [from_state_ndx][to_state_ndx] */
	/* value clocked to TMS to move from one of six stable states to another.
	 * N.B. OOCD clocks TMS from LSB first, so read these right-to-left.
	 * N.B. Reset only needs to be 0b11111, but in JLink an even byte of 1's is more stable.
	 * These extra ones cause no TAP state problem, because we go into reset and stay in reset.
	 */

	/* to state: */
	/*	RESET		 IDLE			DRSHIFT			DRPAUSE			IRSHIFT			IRPAUSE		*/	  /* from state: */
	{B8(1111111, 7), B8(0000000, 7), B8(0010111, 7), B8(0001010, 7), B8(0011011, 7), B8(0010110, 7)}, /* RESET */
	{B8(1111111, 7), B8(0000000, 7), B8(0100101, 7), B8(0000101, 7), B8(0101011, 7), B8(0001011, 7)}, /* IDLE */
	{B8(1111111, 7), B8(0110001, 7), B8(0000000, 7), B8(0000001, 7), B8(0001111, 7), B8(0101111, 7)}, /* DRSHIFT */
	{B8(1111111, 7), B8(0110000, 7), B8(0100000, 7), B8(0010111, 7), B8(0011110, 7), B8(0101111, 7)}, /* DRPAUSE */
	{B8(1111111, 7), B8(0110001, 7), B8(0000111, 7), B8(0010111, 7), B8(0000000, 7), B8(0000001, 7)}, /* IRSHIFT */
	{B8(1111111, 7), B8(0110000, 7), B8(0011100, 7), B8(0010111, 7), B8(0011110, 7), B8(0101111, 7)}, /* IRPAUSE */
};

static const struct tms_sequences short_tms_seqs[6][6] = {
	/* [from_state_ndx][to_state_ndx] */
	/* this is the table submitted by Jeff Williams on 3/30/2009 with this comment:

	OK, I added Peter's version of the state table, and it works OK for
	me on MC1322x. I've recreated the jlink portion of patch with this
	new state table. His changes to my state table are pretty minor in
	terms of total transitions, but Peter feels that his version fixes
	some long-standing problems.
	Jeff

	I added the bit count into the table, reduced RESET column to 7 bits from 8.
	Dick

	state specific comments:
	------------------------
	*->RESET		tried the 5 bit reset and it gave me problems, 7 bits seems to
					work better on ARM9 with ft2232 driver.  (Dick)

	RESET->DRSHIFT add 1 extra clock cycles in the RESET state before advancing.
					needed on ARM9 with ft2232 driver.  (Dick)
					(For a total of *THREE* extra clocks in RESET; NOP.)

	RESET->IRSHIFT add 1 extra clock cycles in the RESET state before advancing.
					needed on ARM9 with ft2232 driver.  (Dick)
					(For a total of *TWO* extra clocks in RESET; NOP.)

	RESET->*		always adds one or more clocks in the target state,
					which should be NOPS; except shift states which (as
					noted above) add those clocks in RESET.

	The X-to-X transitions always add clocks; from *SHIFT, they go
	via IDLE and thus *DO HAVE SIDE EFFECTS* (capture and update).
*/

	/* to state: */
	/*	RESET		IDLE			DRSHIFT			DRPAUSE			IRSHIFT			IRPAUSE */		  /* from state: */
	{B8(1111111, 7), B8(0000000, 7), B8(0010111, 7), B8(0001010, 7), B8(0011011, 7), B8(0010110, 7)}, /* RESET */
	{B8(1111111, 7), B8(0000000, 7), B8(001, 3), B8(0101, 4), B8(0011, 4), B8(01011, 5)},			  /* IDLE */
	{B8(1111111, 7), B8(011, 3), B8(00111, 5), B8(01, 2), B8(001111, 6), B8(0101111, 7)},			  /* DRSHIFT */
	{B8(1111111, 7), B8(011, 3), B8(01, 2), B8(0, 1), B8(001111, 6), B8(0101111, 7)},				  /* DRPAUSE */
	{B8(1111111, 7), B8(011, 3), B8(00111, 5), B8(010111, 6), B8(001111, 6), B8(01, 2)},			  /* IRSHIFT */
	{B8(1111111, 7), B8(011, 3), B8(00111, 5), B8(010111, 6), B8(01, 2), B8(0, 1)}					  /* IRPAUSE */
};

typedef const struct tms_sequences tms_table[6][6];

static tms_table *tms_seqs = &short_tms_seqs;

/* NOTE:  do not change these state names.  They're documented,
 * and we rely on them to match SVF input (except for "RUN/IDLE").
 */
struct name_mapping
{
	enum tap_state symbol;
	const char *name;
};

static const struct name_mapping tap_name_mapping[] = {
	{
		TAP_RESET,
		"RESET",
	},
	{
		TAP_IDLE,
		"RUN/IDLE",
	},
	{
		TAP_DRSELECT,
		"DRSELECT",
	},
	{
		TAP_DRCAPTURE,
		"DRCAPTURE",
	},
	{
		TAP_DRSHIFT,
		"DRSHIFT",
	},
	{
		TAP_DREXIT1,
		"DREXIT1",
	},
	{
		TAP_DRPAUSE,
		"DRPAUSE",
	},
	{
		TAP_DREXIT2,
		"DREXIT2",
	},
	{
		TAP_DRUPDATE,
		"DRUPDATE",
	},
	{
		TAP_IRSELECT,
		"IRSELECT",
	},
	{
		TAP_IRCAPTURE,
		"IRCAPTURE",
	},
	{
		TAP_IRSHIFT,
		"IRSHIFT",
	},
	{
		TAP_IREXIT1,
		"IREXIT1",
	},
	{
		TAP_IRPAUSE,
		"IRPAUSE",
	},
	{
		TAP_IREXIT2,
		"IREXIT2",
	},
	{
		TAP_IRUPDATE,
		"IRUPDATE",
	},

	/* only for input:  accept standard SVF name */
	{
		TAP_IDLE,
		"IDLE",
	},
};

tapc::tapc()
{
	state_follower = TAP_RESET;
	end_state_follower = TAP_RESET;
}

tap_state_t tapc::tap_get_end_state()
{
	return end_state_follower;
}

tap_state_t tapc::tap_get_state(void)
{
	return state_follower;
}

int tapc::tap_get_tms_path(tap_state_t from, tap_state_t to)
{
	return (*tms_seqs)[tap_move_ndx(from)][tap_move_ndx(to)].bits;
}

int tapc::tap_move_ndx(tap_state_t astate)
{
	/* given a stable state, return the index into the tms_seqs[]
	 * array within tap_get_tms_path()
	 */

	int ndx;

	switch (astate)
	{
	case TAP_RESET:
		ndx = 0;
		break;
	case TAP_IDLE:
		ndx = 1;
		break;
	case TAP_DRSHIFT:
		ndx = 2;
		break;
	case TAP_DRPAUSE:
		ndx = 3;
		break;
	case TAP_IRSHIFT:
		ndx = 4;
		break;
	case TAP_IRPAUSE:
		ndx = 5;
		break;
	default:
		LOG_ERROR("FATAL: unstable state \"%s\" in tap_move_ndx()",
				  tap_state_name(astate));
		ndx = 0;
	}

	return ndx;
}

int tapc::tap_get_tms_path_len(tap_state_t from, tap_state_t to)
{
	return (*tms_seqs)[tap_move_ndx(from)][tap_move_ndx(to)].bit_count;
}

void tapc::tap_set_state(tap_state_t new_state)
{
	/* this is the state we think the TAPs are in now, was cur_state */
	state_follower = new_state;
}

const char *tapc::tap_state_name(tap_state_t state)
{
	unsigned i;

	for (i = 0; i < ARRAY_SIZE(tap_name_mapping); i++)
	{
		if (tap_name_mapping[i].symbol == state)
			return tap_name_mapping[i].name;
	}

	return "???";
}

tap_state_t tapc::tap_state_transition(tap_state_t cur_state, bool tms)
{
	tap_state_t new_state = TAP_INVALID;

	/*	A switch is used because it is symbol dependent and not value dependent
	 * like an array.  Also it can check for out of range conditions.
	*/

	if (tms)
	{
		switch (cur_state)
		{
		case TAP_RESET:
			new_state = cur_state;
			break;
		case TAP_IDLE:
		case TAP_DRUPDATE:
		case TAP_IRUPDATE:
			new_state = TAP_DRSELECT;
			break;
		case TAP_DRSELECT:
			new_state = TAP_IRSELECT;
			break;
		case TAP_DRCAPTURE:
		case TAP_DRSHIFT:
			new_state = TAP_DREXIT1;
			break;
		case TAP_DREXIT1:
		case TAP_DREXIT2:
			new_state = TAP_DRUPDATE;
			break;
		case TAP_DRPAUSE:
			new_state = TAP_DREXIT2;
			break;
		case TAP_IRSELECT:
			new_state = TAP_RESET;
			break;
		case TAP_IRCAPTURE:
		case TAP_IRSHIFT:
			new_state = TAP_IREXIT1;
			break;
		case TAP_IREXIT1:
		case TAP_IREXIT2:
			new_state = TAP_IRUPDATE;
			break;
		case TAP_IRPAUSE:
			new_state = TAP_IREXIT2;
			break;
		default:
			break;
		}
	}
	else
	{
		switch (cur_state)
		{
		case TAP_RESET:
		case TAP_IDLE:
		case TAP_DRUPDATE:
		case TAP_IRUPDATE:
			new_state = TAP_IDLE;
			break;
		case TAP_DRSELECT:
			new_state = TAP_DRCAPTURE;
			break;
		case TAP_DRCAPTURE:
		case TAP_DRSHIFT:
		case TAP_DREXIT2:
			new_state = TAP_DRSHIFT;
			break;
		case TAP_DREXIT1:
		case TAP_DRPAUSE:
			new_state = TAP_DRPAUSE;
			break;
		case TAP_IRSELECT:
			new_state = TAP_IRCAPTURE;
			break;
		case TAP_IRCAPTURE:
		case TAP_IRSHIFT:
		case TAP_IREXIT2:
			new_state = TAP_IRSHIFT;
			break;
		case TAP_IREXIT1:
		case TAP_IRPAUSE:
			new_state = TAP_IRPAUSE;
			break;
		default:
			break;
		}
	}

	return new_state;
}

void tapc::tap_set_end_state(tap_state_t new_end_state)
{
	/* this is the state we think the TAPs will be in at completion of the
	 * current TAP operation, was end_state
	*/
	end_state_follower = new_end_state;
}

bool tapc::tap_is_state_stable(tap_state_t astate)
{
    bool is_stable;

    /*	A switch () is used because it is symbol dependent
     * (not value dependent like an array), and can also check bounds.
    */
    switch (astate) {
        case TAP_RESET:
        case TAP_IDLE:
        case TAP_DRSHIFT:
        case TAP_DRPAUSE:
        case TAP_IRSHIFT:
        case TAP_IRPAUSE:
            is_stable = true;
            break;
        default:
            is_stable = false;
    }

    return is_stable;
}
